GETTING THE MEASURE OF BIODIVERSITY

1
GETTING THE MEASURE OF BIODIVERSITY

• RACHAEL BECKSTRAND
• PHILIP COSTASCHUK

2
Main Ideas

• How to define biodiversity?
• Ways to measure biodiversity
• Biodiversity and the relationship to the way
  ecosystems function
• Taxonomic methods used in relation to
  quantifying and studying biodiversity
• Problems in general
• Conclusion
• Questions?

3
How do we define biodiversity?

• The sum of all biotic variation from the level of
  genes to ecosystems.
• The number, variety, and variability of living
  organisms in a quantified area.

4
Methods to Measure Biodiversity

• Species Richness
• Species Evenness
• Disparity
• Species Rarity
• Genetic Variability.

5
Measuring Biodiversity

• Species Richness the total number of given
  species in a quantified area.
• Species Evenness the degree to which the number
  of individual organisms are evenly divided
  between different species of the community.

www.nature.com/cgi-taf
6
Measuring Biodiversity

• Disparity measures the phenotypic differences
  among species resulting from the differences
  genes within a population.
• Species Rarity the rarity of individual
  organisms within a quantified area.

http//www.rit.edu/rhrsbi/GalapagosPages/DarwinFi
nch.html
7
Biodiversity Genetics

• Genetic Variability each population of a species
  contributes to additional biodiversity due to
  variations between genes.

http//magma.nationalgeographic.com/ngm/bestwildli
fe/wallpaper13.html
8
Biodiversity and the Relationship to Ecosystem
Functions

• Diverse communities are typically more stable and
  function more efficiently.
• Loss of a umbrella species leads to a unoccupied
  niche, in turn potentially affecting ecosystem
  processes.
• Extinction events are commonly followed by high
  rates of diversification. Ex) Species turnover

9
Productivity

• Increase of productivity in an area corresponds
  with an increase in biodiversity.
• Ex) tropical rain forest compared to semi-desert
  or tundra

http//www.rainforest.org/projects/balamna/balamna
.html
10
Biodiversity Exotic Species

• Ecosystems with high measures of biodiversity are
  more resistant to invader species.
• Ex) Cheatgrass Tamarisk

http//tncweeds.ucdavis.edu/
http//tncweeds.ucdavis.edu/photos
11
Keystone Umbrella Species

• Species whose presence or resource requirements
  affect ecosystem functions.
• Health of an umbrella species is a way to monitor
  the health of an ecosystem.
• Ex) Northern Spotted Owl Grizzly
  Bears

12
Taxonomy

• New Discoveries
• Grouping together
• Splitting apart
• Phylogenies showing past relationships between
  organisms using evolutionary lineages.

13
Increasing Species Worldwide

• Phylogenic Species Concept
• Computer databases
• Increased human exploration
• Technology electron microscope and evidence
  using mDNA.

14
Species Richness
www.nature.com/cgi-taf
15
Taxonomic methods used in relation to quantifying
biodiversity

• Phylogenic Species Concept
• Biological Species Concept
• Evolutionary Species Concept

16
Phylogenic Species Concept

• taxa are separate species if they can be
  diagnosed as distinct either by phenotypic or
  genotypic information.
• Leads to an increase in the number of species.
• Does not allow for natural variations within
  populations to be listed as separate species.

17
Biological Species Concept

• Groups of organisms that can interbreed freely
  under natural conditions.
• Most commonly used of the three

18
Evolutionary Species Concept

• Groups organisms together using an
  ancestral/descendant relationship that is
  traceable in the fossil record
• Focuses on studying the morphological features of
  closely related organisms.

19
Problems in General

• Measuring biodiversity is ultimately a complex
  process involving many facets.
• Various applications of species concepts either
  divide and/or group organisms together.
• Biodiversity cant be reduced to a single number.
• Studying biodiversity using all ecosystem
  processes at all scales.
• In attempting to preserve biodiversity we often
  are speciesists favoring the cute and popular
  species.

20
Conclusions

• Generally, areas of higher productivity correlate
  with increases in biodiversity.
• Biodiversity is also measured using the genetic
  variability of different populations of a single
  species.
• Biodiversity cant be reduced to a single number,
  thus creating complications when comparing
  biodiversity in different ecosystems.
• The importance of biodiversity is accepted by
  some and disregarded by many others.

21
QUESTIONS

• How do different taxonomic methods create
  potential problems in measuring biodiversity?
• How do difficulties in measuring biodiversity
  create complications for policy makers and
  administrative regulations?
• Can we study all processes at all scales?
• Why should anyone care aboutbiodiversity ?

22
REFERENCES

• Purvis, Andy. Hector, Andy. May 2000. Getting the
  Measure of Biodiversity. Nature Magazine. Vol.405
  pgs 212-219. Berkshire, United Kingdom.www.nature.
  com/cgi-taf
• Wildland Invasive Species Team. July 2002.Vernal,
  UT. Retrieved on 10-26-02 http//tncweeds.ucdavis.
  edu/photos
• Macdonald, Glen. 2003. Biogeography Introduction
  to Space, Time, and Life. New York. John Wiley
  Sons Inc.
• Sartore, Joel. 2002. National Geographic
  Society. Retreived
• 10-20-02 http//magma.nationalgeographic.co
  m/ngm/bestwildlife/ wallpaper13.html
• Dr. Robert Rothman Darwins Finches.
  Retrieved on 10-18-02. http//www.rit.edu/rhrsbi/
  GalapagosPages/DarwinFinch
• Paul Walker. Balam Na Project. Rainforest
  Preserve. 8-28-02 http//www.rainforest.org/projec
  ts/balamna/balamna.html
•      Paul Williams, 2002 Biodiversity Measuring
  the variety of nature and selecting the priority
  areas for conservation. London, 10/23/02,
  http//www.nhm.ac.uk/science/projects/worldmap/
•     Bryant, Peter J., 2001, Biodiversity and
  Conservation A Hypertext book. Irvine,
  10/23/02, http//darwin.bio.uci.edu/sustain/bio65
  /Titlpage.htmTable20of20contents
• Dooley, Laura Lee S., 1982-2002, Biodiversity
  and Protected Areas, Washington D.C., 10/23/03,
  http//www.wri.org/biodiv/

23
Happy Halloween